Although sex differences in research have received considerable attention, few researchers have examined the bias, social context, and process of that research. In analyzing sex differences in academic achievement over the past 10 years, three areas (mathematics, spatial ability, and verbal ability) would appear to establish consistent sex differences. However, upon closer examination of spatial ability research, only one distinct area within the construct, mental rotations, shows sex difference. Other areas, such as horizontality/verticality, do not truly measure spatial ability and therefore should not confound the research and results. The hypotheses for sex differences stem from the nature/nurture or biological versus sociocultural explanations. Biological premises, specifically genes, hormones, brain structure and function, and timing of pubertal changes, have been used to support sex differences in spatial ability and mathematics. However, under closer scrutiny only hormones, and then only as they relate to the levels present in the body, have been correlated with sex differences in cognitive performance. Research on socialization suggests that parental expectations, school structure arrangements, and sex role socialization affect academic achievement. Most research on spatial ability suffers from the chicken and egg dilemma, since it cannot be determined which comes first: spatial skill or interest in spatial activities. Until more scientific rigor is required in studies of sex differences, the research being done will only reinforce stereotypic beliefs. (BL)